Feed mechanism for flexible sheets such as envelopes



Dec. 16, 1952 LAUFFER 2,621,928

FEED MECHANISM FOR FLEXIBLE SHEETS SUCH AS ENVELOPES Filed Feb. 9, 1949 3 Sheets-Sheet l 0ocooo'.ooo

INVENTOR. Jams A? 1/40/72,?

J. R. LAUFFER Dec. 16, 1952 FEED MECHANISM FOR FLEXIBLE SHEETS SUCH AS ENVELOPES 3 Sheets-Sheet 2 Filed Feb. 9, 1949 m m m m HTTGP/VEVS Dec. 16, 1952 J. R. LAUFFER 2,621,923

FEED MECHANISM FOR FLEXIBLE SHEETS SUCH As ENVELOPES Filed Feb. 9, 1.949 3 Sheets-Sheet 5 I INVENTOR.

BY Y/W Patented Dec. 16, 1952 FEED MECHANISM FOR FLEXIBLE SHEETS SUCH AS ENVELOPES Jacob K. Laufier, Valley Stream, N. Y., assignor to Miller-Lauffer Printing Equipment Corp., New York, N. Y., a corporation of New York Application February 9, 1949, Serial No. 75,337

17 Claims.

This invention relates to a mechanism for feeding separate sheets of flexible material such as envelopes. In the embodiment here described for purposes of illustration, there is disclosed a mechanism for feeding envelopes in succession from a stack thereof to a printing position. Most envelopes, and particularly those of crisp paper such as bond, are likely to be somewhat warped and a stack of such envelopes, moving along a conveyor, except when tightly compressed together exhibit noticeable irregularities of spacing. When compared in the hand, certain envelopes seem to be almost flat; others show deformations ranging from barely perceptible to very noticeable deviations from complete flatness. These deformations are due to the crispness of the paper, the effects of folding, local shrinkage when the paste dries, humidity and static. The extent of deformation varies with different kinds of paper, bond paper being an extreme example, but is present in almost all envelopes.

The printing of impressions on envelopes has heretofore been done through the use of reciprocating feed devices or presses whose maximum speed is approximately 10,000 impressions per hour. This speed limitation is imposed by the nature of the reciprocating mechanism itself, which cannot be operated at materially higher speed to produce satisfactory work. While rotary presses can operate on continuous Webs of paper at very much higher speeds (up to 100,000 impressions per hour), the difiiculties inherent in feeding separated sheets, especially folded and pasted sheets such as envelopes, at these speeds have, so far as I am aware, prevented commercial use of rotary presses for printing On separated sheets or on envelopes.

In my prior application Ser. No. 768,744, filed August 15, 1947, I have shown and described a rotary printing press for separated sheets such as envelopes, in which the envelopes are engaged under opposite ends of their flaps by a pair of projecting lugs carried on two geared-together carrier chains moving in parallel paths, the envelopes being thereby successively extracted one by one from the leading end of a moving feed stack to and through a rotary press and thence to a delivery table. This feeding mechanism is herein sometimes called the onward feeder. The present invention was conceived primarily as an improvement in the feeding mechanism of the press shown in said prior application, but in a more general sense is believed to be useful in connection with the feeding of any kind of previously-separated flexible sheets, whether or not envelopes, where it is desired to transfer such sheets one at a time from the leading end of a moving stack thereof towards a point where some further operation, including but not limited to printing, is to be performed upon them. Consequently, while the prior application is referred to as disclosing a printing press and carrier chains with which the present invention is susceptible of being used, it is expressly pointed out that the present invention is not limited to use solely in that connection.

One object of the present invention is to provide a stationary shaping plate located at or adjacent the translation pointwhere the sheets are to be withdrawn one by one from a moving stackwhich in cooperation with suction acting through openings in the plate holds the leading sheet of the stack in an exactly predetermined position for the length of time necessary to enable the onward feeder to gain control of the particular sheet so held.

Another object is to provide a suction-aided shaping plate which will compel the leading sheet of the stack to assume momentarily a predetermined shape which will permit it to be taken hold of by any gripping or engaging elements of the onward feeder.

Another object which may be realized in some forms of the invention, is to regulate and control the suction so that the maximum effect thereof will be utilized in drawing the leading sheet of the stack into contact with, and compelling it to conform to the shape of, the shaping plate, and so that the suction effect will then be diminished while the onward feeder is withdrawing the leading sheet from its position in contact with the shaping plate.

In this specification I show and describe one form of mechanism according to my invention for handling envelopes of letter size. Since the printing mechanism and other mechanisms for handling and delivering the envelopes after printing form no part of the present invention, I do not describe them but merely indicate their general location by legend on the drawings.

Referring to the drawings which are annexed to and form part of this specification- Fig. 1 is a vertical section in a longitudinal plane through the delivery portions of the mechamsm.

Fig. 2 is a top plan view, with some part omitted, of the mechanism shown in Fig. 1.

Fig. 3 is a perspective view of one form of the.

shaping member.

Fig. 4 is a vertical section through the shaping member of Fig. 3 substantially in the plane 44 of Fig. 3.

Fig. 5 is a perspective view of another form of shaping member which, for most purposes, is regarded as the preferred form.

Figs. 6 to 9 inclusive are partial vertical crosssectional views at the translation point, illustrating successive stages of the envelope action at that point, with the warp of the envelopes shown in somewhat exaggerated form for purposes of illustration.

Fig. 6 shows the leading envelope sucked against and conforming in shape to the flat face of the shaping member, with its fiap drawn against the flap sucker, at the moment the flap has been engaged by the lugs 23 of the onward feeder;

Fig. 7 shows the leading envelope partially removed from the stack by upward movement of the lugs, and the lower end of the second envelope being sucked against the lower portion of the shaping member;

Fig. 8 shows the leading envelope lifted clear of the shaping member, and the second envelope sucked nearly into position against the shaping member; and

Fig. 9 shows the last phase in the cycle wherein what has heretofore been called the second envelope has now been drawn completely against the shaping member and its fiap is in process of being opened by the flap sucker.

Referring to Figs. 1 and 2, a bed plate or frame ll, serving as the support for the mechanism hereafter to be described, is itself supported on suitable legs (not shown) so as to be maintained at a convenient working height above the floor. Vertical supports I2 and 13, some of which are shown and others not shown in the drawing, journal and support the axles on which the various wheels and pinions hereinafter mentioned are rotatably mounted. These vertical supports are mounted upon bed plate H or secured in fixed relation thereto.

Secured upon shaft [4 are sprocket wheels l5, l5. Secured upon shaft l6 are sprocket wheels 11. Chains l8, [9 pass over sprocket wheels l5, I5 and I1, and also over other sprocket wheels (not shown) at least one of which in the path of each chain is powered by connection with a suitable motor. The two chains I8 and 19 are arranged to run in parallel paths a predetermined distance apart. The shafting and other connections are such that the chains run at the same speed and are maintained in fixed relation to each other as respects forward movement. Thus a given link of one chain is always opposite a given link of the other, at all stages of rotation. At fixed distances apart, along each chain, there are provided lugs 20, 2| projecting laterally of the chain, each mounted upon a suitable bracket 22 secured to one link of the chain. Each lug is directed toward a corresponding lug on the opposite chain, the two lugs thus paired pointing towards each other and being maintained in alinement during their entire traverse. (See, for example, lugs 20a and 2la in Fig. 2.)

The two chains, moving in unison and in parallel paths, thus form with their paired lugs a carrier for envelopes, designed to transport the latter one at a time from the translation point, hereinafter described, to a printing position, whose location is indicated generally by a legend on Fig. 1, and thereafter to a delivery position beyond the printing position. In so doing, an opposed pair of lugs engages an envelope under the opposite ends of the flap thereof, and thus advances the envelope to and through a rotary printing mechanism, comprising rinting and impression rollers. The type cylinder and impression cylinder are located between the chains, and may imprint on any desired portion of the envelope without interference from the chains and lugs. What has thus far been described is shown in more detail in my prior application Ser. No. 768,744, filed August 15, 1947, and reference thereto is made for a more complete understanding of the structure involved. The present invention is not concerned with the nature of the printing or other operations performed upon the envelopes after they have come under control of the chains I 8, l9, and accordingly the further traverse of those chains and operations associated therewith are not described herein.

If desired, the sprocket wheels serving one chain may be slidably mounted on their supporting shafts, whereby that chain may be moved toward or away from the other chain, thus adapting the machine to be manually adjusted for printing envelopes of different length.

At one portion of their path of travel the chains l8, 19 move, in the form of mechanism here described, in a substantially vertical plane as shown in Fig. 1. At this portion of their travel the lugs 26, 21 move upwardly, and during this upward movement they are arranged and adapted to engage under the opposite ends of the opened flap of an envelope held for this purpose in a vertical plane by the mechanism hereinafter described. The position occupied by the envelope which is ready to be grasped by lugs 20, 2| is herein termed the translation point and is generally indicated by the reference character A on Fig. 1.

The feed of envelopes to the translation point A is in the form of a compact stack moving in a horizontal feed magazine at a suitable speed or speeds under control of powered mechanism tending to advance the stack toward the translation point.

The horizontal feed magazine consists principally of powered feed mechanism such as the wires 23, 24 mounted over sheaves 25 and driven by a suitable source of power not shown. Wires '23 and 24, in their upper horizontal traverse, are arranged to lie upon support plates 26, 21 fixedly sup-ported with respect to bed plate I l. Similarly supported are side plates 28 and 29 serving to guide the lateral margins of the stack of envelopes supported on wires 23, 24.

If desired, one wire and its supporting sheave and plate, and the corresponding side plate, may be slidably mounted on their respective supporting shafts and mounts, whereby they may be moved toward or away from the other wire and plate, thereby permitting the width of the horizontal feed magazine to be manually adjusted for handling envelopes of different length.

In slotted supports 49, 59 resting on or in fixed relation to bed plate H is mounted a cross-rod 5| having a series of perforations 52 therein. Rod 5| passes through slots 58 in the supports and may be adjusted for angular and vertical position by suitable nuts or thumbscrews 53. In a selected preforation of rod 5!, and held there by a thumbscrew, is placed a hold-back finger 54 having a curved and pointed end adapted to rest against the top of the moving stack of envelopes. The position of the pointed end may be adjusted and fixed by means of the nuts and thumbscrews mentioned. By suitably adjusting the pressure of the pointed end of finger 54 on the top of the moving stack of envelopes, this finger will as pressure builds up behind from the forward movement of the stack permit envelopes to escape towards the translation point at a regular rate of speed. In ordinary operation this adjustment is so made that the envelopes in the stack between the pointed end of finger 54 and the translation point A (to the left of the'finger as seen in Fig. 1) are under substantially less pressure, and are looser, than the envelopes in the stack approaching the finger (to the right of the finger as seen in Fig. 1).

For optional use when feeding very tall envelopes, Where the stock in the horizontal feed magazine has a tendency to fall forward or backward, I provide auxiliary chains 30, 3! which, at intervals, carry blocks 32 suitably slotted. Into the slots of blocks 32 there may be manually inserted a guide plate 33, adapted to be manually removed as the block reaches the forward end of its upper line or travel. Chains 3! engage with and are rotated by sprocket wheels 34, and other sprocket wheels not shown, which are suitably powered so that, if the plate 33 is in use, it will advance at substantially the same speed as that at which the stack of envelopes is being advanced by Wires 23, 24 and will support the upper ends of the envelopes.

At the translation point, and generally at right angles to and across the path of travel of the stack feeder, and in or immediately adjacent the path of travel. of the onward feeder, there is positioned a shaping member designated generally by the reference character 35, and shown in more detail in Figs. 3 to 5 inclusive.

The shaping member comprises a plate, preferably of polished steel or other suitable metal, having a shape such that, when the leading envelope is firmly pressed against this plate, said envelope will conform to a predetermined shape when it is at the translation point. In the form of machine here described, it is desired that the leading envelope shall be flat while at this point. Accordingly, the plate is fiat, and is designed to make contact with so much of the surface of the leading envelope presented thereto as is necessary to make said envelope, at the moment of translation, conform substantially to the requirements of flatness which will assure its accurate positioning so that each of a pair of lugs 25, 26 of the chain will accurately come into register with the ends of the flap and will engage and lift the envelope thereby.

In the form of shaping member illustrated in Figs. 3 and 4, the shaping member is box-dike in structure, having an interior chamber. This box-like structure is formed as "follows. Secured to base 36 are wall members 3? and an inner cover plate 38. Spaced from inner cover plate 38 by means of isolated spacers 39 is an outer cover plate 48, there being a substantial region between spacers forming an open slot 45. The exposed outer surface of plate til forms the surface against which the leading envelope is to be positioned at the translation point. Holes ii in the inner cover plate 38 are in approximate axial alinement with openings 42 in the outer cover plate 40. The openings in the outer cover plate 40 are substantially larger than the corresponding holes in the inner cover plate 38, and are preferably masked in part by a grill as shown. An opening 43 in base 36 communicates with tube 44 through which suction is drawn by a suitable fan not shown. A slotted mounting bar 45 permits theshaping member 35 to be suitably mounted and secured at the desired location in chine.

The arrangement is such that when suction is applied through tube 44, atmospheric air will, in the absence of an envelope blocking the opening 12, pass through opening 42 and hole 4|, creating a substantial suction effect in the atmosphere in the immediate vicinity of opening 42. When,

however, the leading envelope is in contact with plate 40 in position tending to seal opening 42, atmospheric air will then bleed into the space between inner plate 38 and outer plate 40 through the slots 45. The structure described affords a passageway communicating with the opening 42 for sucking air through said opening. Thispassageway comprises the space between plates 38 and 40, hole 4|, the open interior of the box-like shaping member, and tube 44. Laterally disposed with respect to this passageway, and adjacent to opening 42, a bleed vent is provided by the slot 45. Thus, air rushing into opening 42, before it has been sealed by an envelope, operates with maximum force to draw the leading envelope into contact with plate ill. However, when the leading envelope covers opening 42, bleed of atmospheric air into the passageway above-described through the slot 45 reduces to a considerable degree the suction which holds the envelope against plate 40.

The shaping member shown in Fig. 3 is indicated as having four openings 42, each alined with a corresponding hole 4| in the inner plate. The number, arrangement and location of these openings in plate 40 is a matter of choice, depending on the character of the sheets (or envelopes) to be handled. I have in the drawing shown an arrangement comprising two holes near the bottom of the envelope and two near the upper corners which has been successfully used in handling ordinary bond letter size envelopes. More holes may be used if desired. The use of one or more holes near the bottom, and one or more near the upper corners of the envelope has the special advantages that suction from the lower holes will be operative to draw the lower edge of a following envelope towards the plate while a preceding envelope is being raised but is still in contact with the upper holes. The shape ing plate 40 is so shaped as to engage the back of an envelope, beneath the flap, leaving the flap free. For this reason the upper surface of shaping member 35, as shown in Fig. 3, slopes downwardly from either end to a low point in the middle. This permits the flap to ride clear over the top of the shaping member. The plate 40 therefore engages only the body portion of the envelope which is beneath the flap.

The type of shaping member shown in Fig. 3 is well suited to use where all the envelopes to be handled are of a size which can be handled by a shaping plate of fixed configuration. I contemplate, however, as hereinabove mentioned, making my device adjustable to handle envelopes of different size or length. In such cases I prefer to make the shaping member in the form of two independent members, a pair of which is shown in perspective in Fig. '5. This pair diifers from the unitary shaping member 35 shown in Fig. 3 merely in the omission of the center section thereof and the provisions of enclosing wall members completing each enclosure. The portions at either end are thus complete and selfcontained units, each having a suitable mounting bar 46a, 46a and each having a suitable suction tube 44a. Except for the division into two parts,

the ma-'.

each self-contained, the construction of these shaping members is the same as the construction of the unitary shaping member shown in Fig. 3. The two portions are intended to be mounted in such position that their outer cover plates 40 lie in the same plane. When so mounted, they may be adjusted to accommodate the machine to envelopes of different lengths.

Above each end of the shaping member there is mounted a flat sucker 41, 48, each comprising a flared-end tube suitably connected to a source of suction, the mouth of the tube being set at an angle to the face 40 of the shaping member as shown.

The hereinabove described construction of the shaping member, with bleed vents along the open slot between the inner and outer cover plates, comprises the preferred form of my invention. While the exact dimensions of holes 4|, openings 42 and slots 45 may be selected with reference to the requirements of the particular sheets to be handled, I have for feeding bond envelopes of letter size used two shaping members substantially as illustrated in Fig. 5, each of which members had two holes 4| having an aggregate crosssectional area of .614 square inch, a slot 45 around the edge of each member having an aggregate cross-sectional area (excluding spacers) of .276 square inch, and each of the two openings 42 having a diameter of H;- of an inch interrupted by crossed bars (as shown in Fig. 5) each bar being /8 inch wide, with minor loss of area due to rounding of corners.

However, the invention is not believed, according to my present information, to be limited to bleed vents of any particularcross-sectional relationship to the cross-sectional area of the opening covered by the envelope, nor to the use of bleed vents as an auxiliary to the suction openings of a shaping plate. As presently advised th invention is believed to comprehend the use of a shaping plate, whether planiform as is best adapted for handling envelopes to be engaged by lugs under their flaps, or curved as may be suited to other types of flexible sheets which are to be engaged by gripping mechanisms other than lugs, where suction operating through or adjacent the shaping surface is employed to cause the leading envelope or sheet to conform to a predetermined shape during the moment it is to be extracted from the stack.

The operation of the above-described apparatus is as follows:

A stack of envelopes resting on wires 23, 24 (and, if desired, also guided and advanced by moving guide plate 33) is moved flap-sides leading toward translation point A by means of the power applied to drive wires 23 and 24. Holdbaok finger 54 releases envelopes successively into a zone in front of the translation point where the envelopes are more loosely arranged in the stack. As the leading envelope approaches. translation point A, it comes under the influence of atmospheric air rushing into holes 42 in the face of plate 4:) of shaping member 35, and is thereby caused to be fiattened against the flat face of plate 40. This operation does not catch the flap of the leading envelope against plate 49 but allows the flap to extend beyond and above the surface of shaping member 35. The flap suckers 41, 48 open the flap and hold it in extended position while the envelope is held against plate 40. The leading envelope, which may if left to itself be considerably warped or misshapen, is thus compelled to assume a fiat position, with its flap outwardly extended, at the moment when the opposite ends of its flap are to be engaged by the lugs 29, 2| of the onward delivery mechanism.

In Fig. 6 the first or leading envelope is shown in fully flattened position against shaping plate 48, covering both the upper and lower openings 42. Because these openings are covered, atmospheric air bleeds to the interior of shaping member 35 through slots 45 thus lessening the force tending to hold the envelope against the plate.

In Fig. 7 the first envelope is shown partly raised by lugs 29 engaging under its flap, this movement having uncovered lower opening 42, but not upper opening 42. At this stage the suction effect through lower opening 42 is at maximum intensity and the lower part of the second envelope is thereby rapidly drawn towards the plate. At the same time the suction effect through upper opening 42 is diminished by the bleed and thus a lessened resistance is provided to the upward sliding movement of this envelope.

In Fig. 8 the first envelope has been raised clear of the shaping plate, and the suction effect of upper opening 42, now at a maximum, is drawing the upper part of the second envelope towards the plate.

In Fig. 9 all parts of the body portion of the second envelope have been drawn firmly against the shaping plate, and flap suckers 41, 48 are drawing the flap to open position. Since all openings 42 are now covered by the envelope, the bleed is operative to diminish the force with which this envelope is held against the plate, and consequently the envelope is held in such a fashion that there will be minimum resistance when, a moment later, another pair of lugs engages the flap and moves the second envelope up to follow the first toward the printing position as shown in Fig. 6.

Where bleed vents are used in the manner described, the effect is that the suction is at maximum value when an envelope is moving towards the plate in a direction normal to its surface, and at minimum value when the envelope is moving away from the plate in a direction parallel to its surface.

While I have herein shown and described, with certain alternates and modifications, the best form of apparatus known to me whereby the advantages of th invention may be realized, I do not intend that the invention shall be limited to the particular form in which the invention is illustrated, but that it shall be taken as embracing all forms and subcombinations thereof comprehended within the following claims.

I claim as my invention:

1. In a machine for feeding flexible sheets, the combination of a stack feeder, an onward feeder for advancing one by one sheets taken from the stack advanced towards said onward feeder by said stack feeder, the paths of travel of said feeders intersecting at substantially right angles, a plate for removing the sheets one by one from the stack as the latter is advanced by said stack feeder, said plate being positioned immediately adjacent the path of travel of the onward feeder and across the path of travel of the stack feeder, said plate having suction openings located in the plate surface to draw the leading sheet in the stack toward the plate and to conform said sheet to a predetermined shape at the moment it is to be engaged by the onward feeder, and a suction passageway adjacent the back surface of the plate and in communication with said suction openings and a vent continuously open to atmosphere in communication with said suction openings and said passageway and cooperating therewith when said sheet rests against the plate and covers at least one of the openings to diminish the suction effect on said sheet through the covered opening.

2. In a machine for feeding flexible sheets, the combination of a stationary shaping plate, power-driven feeding mechanism for continuously advancing a stack of said sheets with their faces juxtaposed in such manner that the leading sheet approaches said plate from a direction generally normal to the surface thereof, a suction opening in said plate adapted to draw the leading sheet into engagement with the plate and thus cause it to conform in shape to the shape of the plate, a vent continuously open to atmosphere communicating with said opening and cooperating with said opening when said sheet rests against said plate and covers said opening to diminish the suction effect on said sheet through said opening, and power-driven feeding mechanism adapted to remove successive leading sheets one by one from a position of engagement with the surface of the shaping plate in a direction generally parallel to said surface.

3. In a machine for feeding envelopes, the combination of an envelope stack feeder for feeding a stack of vertically disposed envelopes horizontally, an envelope feeder for extracting envelopes vertically from the stack one at a time by engagement with their flaps, a vertical plate positioned across the path of travel of the stack feeder and substantially in the plane in which envelopes are to be extracted therefrom, said plate having suction openings located in the plate surface adapted to draw the body of the leading envelope toward the plate and thereby conform it to a predetermined shape with its flap clear of the surface of the plate, and a suction passageway adjacent the back surface of the plate and in communication with said suction openings, and a vent continuously open to atmosphere in communication with said suction openings and said passageway and cooperating therewith when said body rests against the plate and covers at least one of the openings to diminish the suction effect on said body through the covered opening.

4. In a machine for feeding envelopes, the combination of an envelope stack feeder for feeding a stack of vertically disposed envelopes horizontally, an envelope feeder for extracting envelopes vertically from the stack one at a time by engagement with their flaps, a vertical plate positioned across the path of travel of the stack feeder and substantially in the plane in which envelopes are to be extracted therefrom, said plate having suction openings located in the plate surface adapted to draw the body of the leading envelope toward the plate and thereby conform it to a predetermined shape with its flap clear of the surface of the plate and a suction passageway adjacent the back surface of the plate and in communication with said suction openings, and a vent continuously open to atmosphere in communication with said suction openings and said passageway and cooperating therewith when said body rests against the plate and covers at least one of the openings to diminish the suction effect on said body through the covered opening and a flap sucker adjacent said plate surface adapted to open the flap of an envelope held against the plate.

- 5. In a machine for feeding flexible sheets, the

combination of means for causing a stack of said sheets to be delivered so that a portion of the surface of the leading sheet is presented against the surface of a shaping plate, said plate having at least one suction opening in the plate surface adapted to be covered by the leading sheet when the latter comes to rest against the plate, a passageway communicating with said opening for sucking air through said opening to draw said sheet toward the plate, and a vent continuously open to atmosphere and in communication with said passageway and said opening and cooperating therewith, when the sheet rests against the plate and covers said opening, to bleed atmospheric air into the passageway, and an onward feeder for removing the sheets successively from the plate.

6. In a machine for feeding flexible sheets, the combination of means for causing a stack of said sheets to be delivered so that a portion of the surface of the leading sheet is presented against the surface of a shaping plate, said plate having at least two suction openings in the plate surface adapted to be simultaneously covered by different portions of the leading sheet when the latter comes to rest against the surface of the plate, passageways communicating with each of said openings for sucking air through said openings to draw said sheet toward the plate, and vents continuously open to atmosphere and in communication one with each of said passageways and each of said openings and cooperating therewith, when the sheet rests against the plate and covers either opening, to bleed atmospheric air into the passageway adjacent that opening and an onward feeder for removing the sheets successively from the plate.

7. In a machine for feeding flexible sheets, the combination of power-driven feeding mechanism for continuously advancing a stack of said sheets with their faces juxtaposed and delivering, the leading sheet against the surface of a shaping plate, said plate having a suction opening ad jacent the plate surface adapted to be covered by the leading sheet when the latter comes to rest against the plate, a passageway communicating with said opening for sucking air through said opening to draw said sheet toward the plate, and a vent continuously open to atmosphere and in communication with said passageway and said opening and cooperating therewith, when the sheet rests against the plate and covers said open ing, to bleed atmospheric air into the passageway, and an onward feeder for removing the sheets successively from the plate.

8. In a machine for feeding flexible sheets, the combination of a stationary shaping plate, means for causing a stack of said sheets to be moved toward the surface of said plate in such manner that the leading sheet approaches said plate from a direction generally normal to the surface thereof, an opening in said plate adapted to be covered by the leading sheet when said sheet comes in contact with the plate, a passageway communicating with said opening for sucking air through the opening, a vent continuously open to atmosphere and in communication with said passageway and said opening and cooperating therewith, when said opening is covered by the leading sheet, to bleed atmospheric air into the passageway and thus reduce the effective suction at the covered opening, and power-driven feeding mechanism adapted to move successive leading sheets one by one from in contact with the sur- 11 face of the shaping plate in a direction generally parallel to said surface.

9. In a machine for feeding envelopes, the combination of means for causing a stack of said envelopes to be delivered so that a portion of one lateral surface of the leading envelope is presented against a shaping plate, at least one suction opening adjacent the plate surface adapted to be covered by a portion of the surface of the envelope when the latter comes to rest against the plate, a passageway communicating with said opening for sucking air through the opening and thus drawing the envelope towards the plate, and a vent continuously open to atmosphere and in communication with said passageway and said opening and cooperating therewith to bleed air into said passageway when the opening is covered by an envelope, and an onward feeder for removing the sheets successively from the plate.

10. In a machine for feeding envelopes, the combination of means for causing a stack of said envelopes to be delivered so that a portion of one lateral surface of the leading envelope is presented against a shaping plate, at least one suction opening adjacent the plate surface adapted to be covered by the envelope when the latter comes in contact with the plate, a passageway communicating with said opening for sucking air through the opening and thus drawing the envelope towards the plate, a vent continuously open to atmosphere and communicating with said passageway and said opening and cooperating therewith to bleed air into said passageway when the opening is covered by an envelope, and powerdriven feed mechanism adapted to engage under the opposite ends of the flap of the leading envelope while it is in contact with the plate and to move said envelope away from the plate in a direction generally parallel to the surface thereof.

11. In a machine for feeding envelopes, the combination of means for causing a stack of said envelopes to be delivered so that a portion of the flap side of the leading envelope is presented against a shaping plate with the flap free of the plate, at least one suction opening adjacent the plate surface adapted to be covered by the en velope when the latter comes to rest against the plate, a passageway communicating with said opening for sucking air through the opening and thus drawing the envelope towards the plate, and a vent continuously open to atmosphere and communicating with said passageway and said opening and cooperating therewith to bleed air into said passageway when the opening is covered by an envelope.

12. In a machine for feeding envelopes, the combination of means for causing a stack of said envelopes to be delivered so that a portion of the flap side of the leading envelope is presented against a shaping plate with the flap free of the plate, at least one suction opening adjacent the plate surface adapted to be covered by the envelope when the latter comes in contact with the plate, a passageway communicating with said opening for sucking air through the opening and thus drawing the envelope towards the plate, a vent continuously open to atmosphere and communicating with said passageway and said opening and cooperating therewith to bleed air into said passageway when the opening is covered by an envelope, and power-driven feed mechanism adapted to engage under the opposite ends of the flap of the leading envelope while it 12 is in contact with the plate and to move said envelope away from the plate in a direction generally parallel to the surface thereof.

13. In a machine for feeding envelopes, the combination of means for causing a stack of said envelopes to be delivered so that a portion of the flap side of the leading envelope is presented against a shaping plate with the flap free of the plate, at least one suction opening substantially in the plane of the plate adapted to be covered by the envelope when the latter comes in contact with the plate, a passageway communicating with said opening for sucking air through the opening and thus drawing the envelope towards the plate, a vent from said passageway to atmosphere adapted to bleed air into said passageway when the opening is cov ered by an envelope, power-driven feed mechanism adapted to engage under the opposite ends of the flap of the leading envelope while it is in contact with the plate and to move said envelope away from the plate in a direction generally parallel to the surface thereof, and suction means to raise the flap of the leading envelope into elevated position while the envelope is in contact with the plate.

14. In a machine for feeding envelopes to a printer, the combination of a stationary shaping plate, power-driven feeding mechanism for continuously advancing a stack of envelopes flapsides leading towards the surface of said plate so that the leading envelope approaches said plate from a direction generally normal to said surface, said plate being so shaped that the flap of the leading envelope remains free of the plate when the body of the envelope comes in contact with the plate, a plurality of suction openings in the plate adapted to draw the envelope toward the plate and to conform it in shape to the shape of the plate, an atmospheric vent adapted to diminish the suction effect when the envelope has been conformed in shape to the shape of the plate, and power-driven feeding mechanism engaging under opposite ends of the flap of the thus-conformed leading envelope to withdraw it from a position in contact with the plate and to advance it towards a printing position.

15. In a machine for feeding envelopes to a printer, the combination of a stationary shaping plate, power-driven feeding mechanism for continuously advancing a stack of envelopes flapsides leading towards the surface of said plate so that the leading envelope approaches said plate from a direction generally normal to said surface, said plate being so shaped that the flap of the leading envelope remains free of the plate when the body of the envelope comes in contact with the plate, a plurality of suction openings in the plate adapted to draw the body of the envelope toward the plate and to conform it in shape to the shape of the plate, an atmospheric vent adapted to diminish the suction effect when the envelope has been conformed in shape to the shape of the plate, power-driven feeding mechanism engaging under opposite ends of the fiap of the thus-conformed leading envelope to withdraw it from a position in contact with the plate and to advance it towards printing position, and suction means to raise the flap of said envelope into elevated position while the envelope is in contact with the plate.

16. In a machine for feeding sheets, the combination of a powered stack feeder, an onward feeder for extracting sheets one by one from the stack, the paths of travel of the two feeders 1ntersecting at substantially right angles, a holdback finger engaging the movin sheets in the stack feeder and adapted to release them in succession into a zone of diminished pressure as they approach the point where said paths of travel intersect, suction openings adjacent the surface of a shaping plate positioned at said point of intersection adapted to draw sheets toward said plate after they have been released by the hold-back finger, and a suction passageway adjacent the openings and in communication therewith, and a vent continuously open to atmosphere in communication with said suction openings and said passageway and cooperating therewith when a sheet rests against said plate and covers at least one of the openings to diminish the suction effect on said sheet through the covered opening.

1'7. In a machine for feeding envelopes, the combination of an envelope stack feeder for feedins a stack of vertically disposed envelopes horizontally, an envelope feeder for extracting envelopes one by one vertically from the stack by engagement with their flaps, a vertical plate positioned across the path of travel of the stack feeder with its face substantially in the plane in which envelopes are to be extracted from the stack, suction openings adjacent the surface of 14 said plate, and a suction passageway adjacent the openings and in communication therewith, and a vent continuously open to atmosphere in communication with said suction openings and said passageway and cooperating therewith when an envelope rests against said plate and covers at least one of said openings to diminish the suction efiect on said envelope through the covered opening and a hold-back finger located adjacent the face of said plate and adapted to engage the upper surface of the envelopes in the stack feeder as they approach the plate and to release them in succession under reduced pressure from following envelopes as they move towards said plate.

JACOB R. LAUFFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PA'I'ENTS Number Name Date 769,927 Zeh Sept. 13, 1904 868,093 Jenkins Oct. 15, 1907 955,112 Abrams Apr. 12, 1910 1,724,199 Hoag Aug. 13, 1929 2,449,690 Chapman Sept. 21, 1948 

